Process of manufacturing rubber articles



R. F. KINSLEY PROCESS (DP-MANUFACTURING RUB BER ARTICLES Sept. 11, 1928. 1,684,100

Filed May 19, 1924" s Sh eets S heet 1 DDDDDDD. DDDDDDD DDDDDDD" DDDDDDD DDDD'DDD N DDDDDDD- Richard FKmic y R. F. KINSLEY PROCESS OF MANUFACTURING RUBBER ARTICLES Sept. 11, 1928.

Filed May 1 9, 1924 3 Sheets-Sheet E] Ric/yard FKI'nSZe Sept. 11,1928. 1,384,100

F. KINSLEY PROCESS OF MANUFACTURING RUBiBER ARTICLES- Filed May 19, 1924 s Sheets-Sheet 3 3T 7 R ighard' FM /e3 Patented Sept. 11, 1928.

Brown F. KrnsLEY,

OF CHICAGO, ILLINOIS, ASSIGNOR T0 DRYDEN RUBBER COH- lANY, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

PROCESS 0E MANUFACTURING ARTICLES.

Application filed May 19,

This invention relates to the manufacture of rubber articles, more particularly from ground waste vulcanized rubber scrap.

I Rubber articles are formed with varying amounts of sulphur in their composition.

Thus for example automobile inner tubes are low in sulphur and hard rubber articles very high in sulphur. Further, nearly all rubber articles contain free uncombincd sulphur.

It is always possible to make rubber articles from ground waste vulcanized rubber scrap without the addition oi crude rubber provided that a higher percentage of combined sulphur than the scrap. It is not always poss ble, however, to proceed in the opposite drrection, i. e. to make articles of lower sulphur content than the scrap, without adding raw unvulcanized rubber to the mix.

One of the principal objects of this invention is to provide an improved process and means for making articles from waste vulcanized rubber scrap.

A further object oi the invention is to improve the method and means for making rubber articles whether wholly from waste vulcanized scrap, wholly from raw rubber or from mixtures of the two or from reclaimed rubber.

Other and further important objects of this invention will be apparent from the dis closures in the specification and drawings.

Apparatus (in a preferred form) suitable for carrying the invention into effect is illustrated on the drawings and hereinafter more fully described.

On the drawings Figure 1 shows a side elevation of a vulcanizing press suitable for carrying out the process.

Figure 2 is a vertical section through a portion of the press at the end of the first operation.

Figure 3 is a plan view of for making the blanks.

the grid used Figure 4c is a vertical section through a portion of'the press showing the grid in po-Q sition for making the blanks. v Figure 5 is a view similar to Figure ii showing the end of the blank making operation.

Figure 6 is a section through the final heel making dies.

the rubber in the article has 1924. Serial no. 714,195.

Figure 7 is a vertical section through a portion of a vulcanizing press suitable for carrying out a modified form of process.

Figure 8 is a view similar to Figure 7 illustrating afurther form of process.

Figure 9 is a section through one of the blanks made by the apparatus shown in Figure 8. i

As shown on the drawings in all forms of process set forth the usual hydraulic vulcanizing press 10 is employed in which are arranged male and female dies 11 and 12. In the form of process. shown in Figures 1 to 6 no grid or other mechanical appliance is employed in connection with the dies 11 and 12. In carrying out this process the mix, preferably consisting of finely ground waste rubber scrap without admixture with any raw rubber but usually containing added amounts of sulphur and if desired one or more fillingiiiaterials or the like inserted in the die 12. Pi essure is then applied to force the die 1.1 down onto the material within the die 12. This pressure only applied for a few seconds to consolidate the matter in the die 12 into a sheet 13. As the dies are heated the consolidating action of the pressure is aided by heat.

The finely ground mix may to gr eat ad vantage be heated prior to insertion into the die 12 since rubber. especiallyin finely divided form. is a poor conductor ohheat so that the transference of heat from rt-heidies to the center of the mass is necessarily a slow operation. This pro-heating may conveniently be carried out in a rotating drum.

After consolidation into a sheet the next step is to place a grid 14 upon the sheet 13. In this grid are formed a series oi apertures 15. In the form shown. which is adapted torthe manufacture of rubber heels, these apertures are of substantially the same contour as thciinished heels but of smaller area.

The next step is to press the grid downwards onto the layer 18 in order to force the rubber into the apertures 15, as shown in Figure 5, to form blanks 16. This operation takes about two minutes and the rubber is partly cured in the operation soiar as excess sulphur in the waste and added sulphur is concerned. In other words the vulcanization has proceeded part way between of such heat.

no special pre-h'eating treatment is applied the mix should preferably be used immediately after grinding to obtain the advantage when that is done to supplement the heat of grinding b treatment in a heating drum.

lVhile tie invent'on has been described more particularly in connection with the manufacture of articles wholly from ground waste vulcanized rubber scrap it is also ap plicable to other mixes consisting in whole orin part ofunvulcanized raw rubber or of reclaimed rubber. The. invention is not restricted to the use of finely ground rubber and in some cases the rubber may be worked into sheets upon mixing rolls andthen cut into squares of the size of the mould 12 and inserted therein. The grid 14 is then laid on top and the material of the-sheet squeezed into the apertures in the grid to form blanks .for the final heel making operation. In

some cases the position of the grid and sheet maybe reversed. In this way there is little It is desirable, however, even.

or no scrap to be re-worked on the rolls as is always the case where the blanks are cut or punched from such sheets. In general continued rte-working of even unvulcanized. rubber is not desirable and by the method just described such re-working is almost wholly avoided.

I am aware that various details of oper ation and construction of apparatus em-- ployed may be varied through a wide ran e wit iout departing from the principles of thls invention, and therefore do not purpose limiting the patent granted otherwise than as necessitated by the prior art.

I claim as my invention:

The process of forming rubber heels from,

ground waste 'vulcanized rubber includin forming partially cured blanks therefrom 0 smaller area but greater th'ekness than the finished article, inserting these blanks in a mould placing a la er of rubber material thereon of greater *p astieity and lesser elasticity than that of the blank and "subjecting the whole to heat and pressure toproduce the finished article.

In testimony whereof I have hereunto subscribed my name.

RICHARD F. KINSLEY. 

